Re-configurable trigger assembly

ABSTRACT

Described is an improved trigger assembly for use in an electronic device. The trigger assembly includes a pressure sensitive member and a trigger button. The pressure sensitive member includes two or more conductive lines. The pressure sensitive member is secured to a portion of the mobile terminal. The trigger button is secured to the mobile terminal in a manner such that a force applied to the trigger button causes a resultant force to be applied on the pressure sensitive member. The force applied on the pressure sensitive member causes a change in an electrical property between at least two of the conductive lines. A module measures the electrical property between the conductive lines. A function of the device is initiated depending on a comparison of the measured electrical property to a threshold value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/160,772, filed on Jun. 3, 2002 and entitled, “RE-CONFIGURABLE TRIGGERASSEMBLY”, the entirety of which is incorporated herein by reference.

BACKGROUND INFORMATION

Triggers or buttons are commonly used on electronic devices. Forinstance, triggers are employed on mobile computing terminals, bar codescanners, cellular phones, portable digital assistants (PDAs), etc. Thetrigger is used to initiate certain functions on the device. Forinstance, the trigger may activate a module to capture bar codeinformation. The module may be a laser based bar code scanner or animager. The trigger may also activate a speaker module for telephoniccommunication, it may activate a data transfer function or it may beused to navigate through menu options on a display.

FIG. 1 shows a typical conventional trigger assembly for a mobileterminal. The assembly consists of several mechanical type componentsthat are utilized to actuate electrical switch assembly 8 upon thedepression of a trigger button 4. Switch assembly 8 has two switchelements 8 a and 8 b to activate two functions on the mobile terminal.Switch assembly 8 can include contacts 5 or wires/flex that connect tocircuitry within the mobile terminal. A trigger housing 9 connectstrigger button 4 with mobile terminal housing 10. A trigger bezel 6connects trigger button 4 with trigger housing 9. A leaf spring 3 actsto restore trigger button 4 to its initial position after trigger button4 is depressed. Sealing in terms of electrostatic discharge (ESD),water, and dust, requires the addition of gaskets to the triggerassembly.

The above-described trigger assembly has a number of shortcomings. Thetrigger assembly requires a user to assert a fixed amount of force andstroke in order to activate the trigger. Also, the trigger assembly mustinclude gaskets to environmentally seal the terminal. Even with suchgaskets, water and debris may still enter the terminal. In addition, thetrigger assembly has a limited number of life cycles due to wear on thevarious moving parts. In addition, the trigger assembly requires arelatively significant amount of labor to manufacture.

SUMMARY OF THE INVENTION

Described is an improved trigger assembly for use in a mobile terminalor similar device. The trigger assembly includes a pressure sensitivemember and a trigger button. The pressure sensitive member is secured toa portion of the mobile terminal. The trigger button is secured to themobile terminal in a manner such that a force applied to the triggerbutton causes a resultant force to be applied on the pressure sensitivemember.

The pressure sensitive member includes a connector that is coupled tocircuitry on the mobile terminal. The assertion of a force on thetrigger button changes electronic properties of the pressure sensitivemember. In one embodiment of the invention, asserting a force on thetrigger button causes a change in the electrical resistance the pressuresensitive member. For example, the force causes a conductive layer ofthe pressure sensitive member to come in contact with conductive traceswithin the pressure sensitive member. As the force increases (within acertain range), the electrical resistance of the conductive tracesdecreases. In another embodiment of the invention, asserting a force onthe trigger button causes a change in the capacitance of the pressuresensitive member. In yet another embodiment, a piezoelectric element isincluded in the pressure sensitive member wherein when pressure isapplied to the pressure sensitive member there is a change in potentialbetween the opposite sides of piezoelectric element.

In a preferred embodiment of the present invention, at least a portionof the pressure sensitive member is insert molded into the mobileterminal housing, creating an integral seal.

In another aspect of the present invention, the triggering systemincludes a user force adjustment feature wherein a user can adjust theamount of force required to activate the trigger.

In yet another embodiment of the invention, the triggering systemincludes a user position adjustment feature, wherein a user can adjustthe number of trigger positions, i.e., 1, 2, or 3 positions, foractivation of several different features.

In yet another embodiment of the invention, the triggering systemincludes a pressure sensitive member that includes multiple pressuresensitive target areas which would enable a user to activate severaldifferent features by depressing different areas of the trigger.

In yet another embodiment of the invention, the triggering systemincludes a tactile or audio feedback mechanism.

These and other objects, advantages and features of the invention willbecome better understood with regard to the following description,appended claims and accompanying figures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a conventional trigger assembly used in a mobile terminal;

FIG. 2 shows an exemplary embodiment of a trigger assembly according tothe present invention including a portion of a housing of a mobileterminal;

FIG. 3 shows an exploded view of a trigger assembly of a preferredembodiment of the present invention;

FIG. 4 shows a pressure sensitive member of a preferred embodiment ofthe present invention;

FIG. 5 shows a side view of an alternative embodiment of the pressuresensitive member of the present invention;

FIG. 6 shows another alternative embodiment of the pressure sensitivemember of the present invention; and

FIG. 7 shows a side view of an alternative embodiment of the pressuresensitive member of the present invention.

DETAILED DESCRIPTION

FIG. 2 shows a portion of a mobile terminal housing 10 having atriggering assembly according to the present invention. FIG. 3 shows anexploded view of the trigger assembly. The triggering assembly includesa trigger button 14 and a pressure sensitive member 20. A triggerhousing 19 connects trigger button 14 with mobile terminal housing 10.Trigger housing 19 is preferable comprised of a rubber over mold.Trigger button 14 is secured to trigger housing 19 via an interface fitor other fastening techniques known to those of skill in the art.Trigger button 14 includes a front section 17 for engagement with one ormore of the user's fingers. Opposite front section 17 of trigger button14 is a back section 18. When a user engages trigger button 14, backsection 18 asserts a force on trigger housing 19 which asserts a forceon a target area 22 of pressure sensitive member 20. In an alternativeembodiment of the invention the trigger button could directly assert theforce on the target area of the pressure sensitive member.

In a preferred embodiment of the present invention, pressure sensitivemember 20 is insert molded into mobile terminal housing 10. Thetechniques for molding pressure sensitive member 20 into mobile terminalhousing 10 are those traditionally used in the plastic molding industry.The molded trigger assembly of the present invention is moreenvironmentally sealed than traditional triggering assemblies that tendto rely on elastic gaskets. Gaskets may allow the passage of water anddebris into the mobile terminal and eventually wear after repeated use.In addition, tooling parts to manufacture the gaskets and labor costs toinstall the gaskets are eliminated under the present invention. Inanother embodiment of the present invention, an adhesive material isapplied between pressure sensitive member 20 and mobile terminal housing10 to secure the two components.

FIG. 4 shows an exemplary embodiment of pressure sensitive member 20according to the present invention. Target area 22 of pressure sensitivemember 20 is connected to flexible tail 24. Flexible tail 24 isconnected to a connector 26. Connector 26 electrically couples pressuresensitive member 20 to a circuitry on the mobile terminal.

The operation of a preferred embodiment of pressure sensitive member 20will now be described with reference to FIGS. 2 and 4. Connector 26includes two contacts, 31 and 32, that interface with contacts withinthe mobile terminal. Electrically connected to contacts 31 and 32 withinpressure sensitive member 20 are, respectively, conductive traces 35 and36. Within target area 22, conductive traces 35 and 36 are arranged in apattern that covers a substantial portion of the surface area of targetarea 22. Preferably, conductive traces 35 and 36 are arranged in azigzag pattern. One skilled in the art would recognize that theconductive traces could be configured in a number of different patternswithout departing from the nature of the present invention. Conductivetraces 35 and 36 terminate at a distal end of pressure sensitive member20. There is a gap between conductive trace 35 and conductive trace 36.Pressure sensitive member 20 includes a conductive layer 37 inlongitudinal relation to conductive traces 35 and 36. Conductive lay 37may be located either under and/or over conductive traces 35 and 36.Conductive layer 37 could be comprised of a number of differentconductive materials. In a preferred embodiment, conductive layer 37 iscomprised of conductive rubber. Pressure sensitive member 20 isconfigured such that when there is no pressure applied on it, noelectric current (or very little current) will flow between conductivetrace 35 and conductive trace 36. As pressure is applied to pressuresensitive member 20, conductive layer 37 comes in contact withconductive traces 35 and 36. Thus, conductive layer 37 enables anelectric current to flow between conductive trace 35 and conductivetrace 36. As more pressure is applied to pressure sensitive member 20,the contact between conductive layer 37 and conductive traces 35 and 36improves (decreasing the electrical resistance). As a result, as thepressure applied to pressure sensitive member 20 increases, the currentflow between conductive traces 35 and 36 increases (within a certainrange of pressure).

Connector 26 is fastened to a terminal connector 7 within the mobileterminal. Circuitry within the mobile terminal measures the currentbetween conductive traces 35 and 36. In one embodiment of the invention,the measured current is compared to a threshold value. If the measuredcurrent between conductive traces 35 and 36 is more than the thresholdvalue, a certain function of the mobile terminal is activated. Forinstance, if the measured current exceeds the threshold value, themobile terminal will scan a bar code with a laser-based scanner, take animage using an imaging module, activate a microphone on a telephoniccommunication module or send data over a wireless network. If themeasured current is less than the threshold value, the functionality ofthe mobile terminal will not be activated.

In one embodiment of the present invention, different functions of themobile terminal can be activated depending on the amount of force a userapplies to the trigger button 14. For instance, if the measured currentbetween conductive traces 35 and 36 is between an initial threshold anda second threshold, a first function of the mobile terminal isactivated. In the event the measured current between conductive traces35 and 36 is between the second threshold and a third threshold, asecond function of the mobile terminal is activated. In a similarmanner, the system could be designed to activate more than two functionsof the mobile terminal.

The embodiments described above are based on measuring a current thatflows between two conductive traces. One skilled in the art wouldrecognize that other electrical signals could be measured to detect theforce applied to the trigger button without departing from the nature ofthe invention. For instance, the assertion of force on the pressuresensitive member could cause a measurable change in capacitance orvoltage. FIG. 7 shows a side view of an alternative embodiment ofpressure sensitive member 20 of the present invention. Pressuresensitive member 20 includes a dialectic material 50. On opposite sidesof dialectic material 50 are a first conductive layer 62 and a secondconductive layer 64. First conductive layer 62 and second conductivelayer 64 are connected, respectively, to conductive traces 68 and 66.Conductive trace 66 is connected to contact 31. Conductive trace 68 isconnected to contact 32 (not shown in FIG. 7). As recognized by thoseskilled in the art, when a pressure is applied to first conductive layer62 and/or second conductive layer 64 such that the distance between thetwo layers changes, the capacitance measured between contacts 31 and 32changes. The change in capacitance can be measured at contacts 31 and 32to detect the amount of force asserted on pressure sensitive member 20.The measured change in capacitance between contacts 31 and 32 iscompared to a threshold value. In a manner similar to the embodimentdescribed above, if the measured current between contacts 31 and 32 ismore than the threshold value, a certain function of the mobile terminalis activated.

In a preferred embodiment of the invention, the amount of force requiredto activate a function of the mobile terminal is user adjustable.Preferably, this is accomplished by adjusting the threshold valuenecessary to activate the function of the mobile terminal. A user whowants to change the sensitivity of the trigger can put the mobile devicein trigger adjustment mode. This may be done via a user interface, e.g.,a touch screen display. In a preferred embodiment, the user sets thethreshold value by putting the mobile device in the trigger adjustmentmode and pressing the trigger. The amount of force the user asserts isused to set the threshold value.

In another embodiment of the invention, the user can adjust thethreshold value by scanning barcodes dedicated to that function. Forinstance, a user manual for the mobile terminal could include triggerforce adjustment barcodes that correspond to light force, medium forceand heavy force. The user could simply scan the barcode that correspondsto the setting preferred by the user.

In one embodiment of the invention, after a user enters a useridentification code into the mobile terminal, the system automaticallysets the threshold value to that user's preferred, preset thresholdsetting. The mobile terminal accesses a database (located eitherremotely or locally) that matches the user identification codes to apreferred threshold setting. After the user enters his or heridentification code, the system determines the correct threshold valueand sets it for that particular user.

FIG. 5 shows a side view of an alternative embodiment of pressuresensitive member 20 of the present invention that includes piezoelectriccomponents. Pressure sensitive member 20 includes a piezoelectriccomponent such as a piezoceramic 50. On opposite sides of piezoceramic50 are a first conductive layer 52 and a second conductive layer 54.First conductive layer 52 and second conductive layer 54 are connected,respectively, to conductive traces 58 and 56. Conductive trace 56 isconnected to contact 31. Conductive trace 58 is connected to contact 32(not shown in FIG. 5). As recognized by those skilled in the art, when apressure is applied to piezoceramic 50, there is a change in potentialbetween the opposite sides of piezoceramic 50. The change in potentialcan be measured at contacts 31 and 32 to detect the amount of forceasserted on pressure sensitive member 20. The measured change inpotential between contacts 31 and 32 is compared to a threshold value.In a manner similar to the embodiment described above, if the measuredcurrent between contacts 31 and 32 is more than the threshold value, acertain function of the mobile terminal is activated.

FIG. 6 shows an embodiment of pressure sensitive member 20 having twopressure sensitive target areas 22 a and 22 b. This embodiment is usedto activate multiple functions of the mobile terminal. When a userpresses the trigger button with one of his fingers, a force is appliedto target area 22 a activating a particular function of the mobileterminal. When the user presses the trigger button with another finger,a force is applied to target area 22 b activating another function ofthe mobile terminal. This embodiment of the invention operates in amanner similar to that described above except that there are two pairsof conductive traces, 35 a, 36 a and 35 b, 36 b, and two pairs ofcontacts 31 a, 32 b and 31 b and 32 b. A force applied to target area 22a is detected by measuring the current between 32 a and 31 a. A forceapplied to target area 22 b is detected by measuring the current between32 b and 31 b. In alternative embodiments of the invention, pressuresensitive member 20 could have more than two pressure sensitive targetareas. One skilled in the art would recognize that the multiple pressuresensitive mode described herein could also be accomplished by usingpiezoceramic elements with pressure sensitive member 20 in a mannersimilar to that described above.

In one embodiment of the invention, the functions activated on themobile terminal could be initiated depending on a combination of theuser's finger assertions. For instance, consider an embodiment whereinthe pressure sensitive member 20 includes three target areas, T1, T2 andT3. When a user asserts a force on any one of these target areas, aparticular function, e.g., F1, F2 or F3, of the mobile terminal isinitiated. If forces are asserted simultaneously on T1 and T2, a fourthfunction, F4, could be initiated. Likewise, the assertion of forcessimultaneously on T1 and T3 could result in a fifth function, F5, couldbe initiated. In addition, as described above, each target area couldactivate multiple functions depending upon the amount for force appliedto the target area. This significantly increases the number of functionsthat can be activated by the trigger button. In the embodiment describedherein, the functionality of the mobile terminal could be controlled ina manner analogous to a musical instrument. While it is recognized thatit may take a great deal of practice to become proficient at applyingthe various combinations of forces and/or amounts of forces on thetrigger button, the benefits are significant. The user of a mobiledevice that has multiple functions can activate multiple functions in aninstant with a single hand.

In a preferred embodiment of the invention, the trigger assemblyincludes a tactile feedback mechanism. After the amount of forceasserted on the trigger button exceeds the threshold value, the tactilefeedback mechanism creates a slight movement in the trigger button toallow a user to feel that the trigger assembly was properly engaged. Thetactile feedback in the trigger button could be created by a smallsolenoid or spring within the trigger assembly.

In another preferred embodiment of the invention, the trigger assemblyincludes an audio feedback mechanism. The audio feedback could begenerated within a speaker on the mobile terminal. Preferably, thespeaker is the main speaker used in the mobile terminal. After theamount of force asserted on the trigger button exceeds the thresholdvalue, the system sends an audio signal to the speaker. In a preferredembodiment, the sound from the speaker is user selectable. The user canselect from a list of sounds that he or she would like the terminal tomake in response to a trigger actuation. In an embodiment of theinvention where there are multiple functions activated by the triggerassembly, the trigger assembly could be configured so that the speakermakes different sounds depending upon the function by activated.

The embodiments described above are described with respect to a triggerbutton on a handle on a mobile terminal. It should be recognized thatthe trigger assembly of the present invention could be located on otherareas of the mobile terminal. For instance, the trigger button could belocated on the side or face of the mobile terminal.

The herein described embodiments of the present invention are intendedto provide the preferred embodiments of the present inventions currentlycontemplated by the applicant. It would be obvious to any one of skillin the relevant art, based on the herein described examples thatnumerous modifications could be made to the described preferredembodiments without straying from the present invention. Accordingly,the herein described embodiments are merely exemplary in nature and arenot intended to represent every possible embodiment of the presentinvention.

1. A trigger assembly that activates a function of a host device,comprising: a pressure sensitive member that varies electric current orvoltage values as a function of pressure applied thereto; and a triggerthat selectively applies pressure to the pressure sensitive member toactivate one or more functions of the host device, wherein thresholdsfor the electric current or voltage values are user adjustable so as tocorrespond to respective functions of the host device.
 2. The triggerassembly of claim 1 further comprising a comparator that compareselectric current or voltage values in the pressure sensitive member withthe thresholds.
 3. The trigger assembly of claim 2, the thresholdsadjustable via scan of a barcode, by the user.
 4. The trigger assemblyof claim 1, the thresholds adjustable via an adjustment mode of thetrigger assembly.
 5. The trigger assembly of claim 1 further comprisinga unit that measures electrical properties of the pressure sensitivemember.
 6. The trigger assembly of claim 1, the pressure sensitivemember includes a piezoceramic element.
 7. The trigger assembly of claim1, the pressure sensitive member includes dielectric material.
 8. Thetrigger assembly of claim 1 further comprising a memory that stores thethresholds.
 9. The trigger assembly of claim 1, the pressure sensitivemember with a capacitance that is variable as a function of pressureapplied.
 10. The trigger assembly of claim 1, the pressure sensitivemember includes conductive lines with variable electrical propertiestherebetween.
 11. A method of triggering a function in a portable unitcomprising: activating the function when a threshold value of a triggeris reached upon pressing thereupon, and adjusting the threshold value toanother value by a user, to regulate sensitivity of triggering thefunction.
 12. The method of claim 11 further comprising storingthreshold values in a memory of the portable unit.
 13. The method ofclaim 11, act of adjusting the threshold value to another value by auser is performed via scanning a bar code.
 14. The method of claim 11further comprising varying an electrical property of a pressuresensitive member associated with the trigger, based on pressure appliedthereto.
 15. The method of claim 14 further comprising increasing thepressure to activate the function.
 16. The method of claim 14, theadjusting act further comprising placing the portable unit in a triggeradjustment mode and depressing the trigger.
 17. The method of claim 14further comprising measuring the electrical property in the pressuresensitive member.
 18. The method of claim 17 further comprisingcomparing the electrical property with the threshold value.
 19. Themethod of claim 17 further comprising varying a capacitance of thepressure sensitive member based on the pressure.
 20. A trigger assemblycomprising: pressure sensitive means for varying an electrical propertyas a result of pressure applied thereto; means for applying pressure tothe pressure sensitive means, to activate one or more functions of adevice that hosts the trigger assembly, upon reaching a threshold value,and; means for adjusting the threshold value by a user.